1. Field of the Invention
This invention relates generally to disk drives, and more particularly, to flexures for supporting a head in a disk drive.
2. Description of the Related Art
Disk drives (e.g., magnetic disk drives) utilize a rotating media surface and a head that is suspended above the rotating media surface. The head typically includes a slider (e.g., comprising a ceramic material), one or more transducers (e.g., read transducer, write transducer), and heater elements. The slider comprises a surface facing the rotating media surface and serving as an air bearing to suspend the head above the rotating media surface. The head is attached to a flexure that helps position and move the head from track to track across the rotating media surface. The flexure provides flexibility for pitch and roll motion of the head relative to the rotating media surface.
Flexures typically have a composite or laminate structure with a thin structural layer (e.g., stainless steel), an electrically insulating layer, and patterned electrical leads formed thereon. The flexure is designed to have high lateral stiffness but sufficiently low pitch and roll stiffnesses so that the head can pitch and roll in response to undulations of the rotating media surface without excessive torques acting upon the air bearing. Lower and lower pitch and roll stiffnesses of the flexure are desirable as slider dimensions and fly heights are reduced.
Previous attempts to lower the pitch and roll stiffnesses of the flexure have included: (1) using outboard traces and making the copper traces more flexible to reduce the copper trace stiffness contribution to the total stiffness of the flexure; (2) forming curved traces to reduce the copper trace stiffness contribution; and (3) reducing the thickness of the flexure by using thinner layers (e.g., stainless steel thinner than 15 microns). However these techniques have significant disadvantages. For example, outboard traces may be more easily damaged during head gimbal assembly (HGA) or head stack assembly (HSA) processes. Curved traces can reduce maximum data bandwidth. Thinner flexures may be more prone to damage through ultrasonic cleaning processes, introducing yield problems at both the suspension component level and at the HGA level. Therefore, there is a need in the art for an improved way to reduce the pitch and/or roll stiffnesses of a flexure supporting a head in a disk drive.